In a general sense, an ontology is the philosophical study of basic concepts and their relations to each other. Ontology's deal with questions concerning what entities can be said to exist, how such entities can be logically grouped together in a hierarchy, and what similarities and/or differences can be used to segregate ontological concept groups from each other. In computer and information science, the general ontology translates into a naming and definition of types, properties, and relationships that fundamentally exist in a particular computing domain. For example, an ontology can compartmentalize variables needed for a set of computations and establish relationships between those variables.